That's a bit presumptuous. My issue with Safari isn't that sites don't work; its seems comparable to Chrome in that regard. But using it doesn't feel as nice as Firefox or Chrome. It's harder to find features I need. Though to be honest, I find all browsers a bit lacking. I want more granular control over which cookies to accept and for how long, and how exactly to treat various sites.

And I certainly don't blame browsers for badly written sites, but blaming the site doesn't magically make it work either. Having less sites work for me is still a worse experience, no matter whose fault it is.